Regulatory Capital Requirements (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Regulatory Capital Requirements
Excess Regulatory Capital	$ 10,000
TWL
Regulatory Capital Requirements
Regulatory Capital	13,091	$ 18,986
Regulatory Capital Requirement	2,115	2,698
Excess Regulatory Capital	10,976	16,288
DW
Regulatory Capital Requirements
Regulatory Capital	47,260	41,164
Regulatory Capital Requirement	1,907	1,803
Excess Regulatory Capital	45,353	39,361
TWD
Regulatory Capital Requirements
Regulatory Capital	18,767	24,042
Regulatory Capital Requirement	459	599
Excess Regulatory Capital	18,308	23,443
TEL
Regulatory Capital Requirements
Regulatory Capital	52,499	46,157
Regulatory Capital Requirement	20,331	17,493
Excess Regulatory Capital	32,168	28,664
TWJ
Regulatory Capital Requirements
Regulatory Capital	9,719	10,592
Regulatory Capital Requirement	7,927	3,413
Excess Regulatory Capital	1,792	7,179
TWEU
Regulatory Capital Requirements
Regulatory Capital	6,342
Regulatory Capital Requirement	1,652
Excess Regulatory Capital	4,690
TW SEF
Regulatory Capital Requirements
Financial Resources	24,766	31,232
Required Financial Resources	10,500	10,500
Excess Financial Resources	14,266	20,732
Liquid Financial Assets	13,207	16,662
Required Liquid Financial Assets	5,250	5,250
Excess Liquid Financial Assets	7,957	11,412
DW SEF
Regulatory Capital Requirements
Financial Resources	15,864	17,837
Required Financial Resources	5,479	5,169
Excess Financial Resources	10,385	12,668
Liquid Financial Assets	9,631	11,888
Required Liquid Financial Assets	2,740	2,585
Excess Liquid Financial Assets	$ 6,891	$ 9,303